抄録
This paper describes the topography of the following four districts: (1) The Toyama plain, (2) The mountainous district between Hunadu and Sasadu, (3) The Hiba plateau, (4) The Hirayu district.
(1) There are two drowned valleys near the mouth of the River Zindû, one situated at the mouth of that river, and the other near the coast of Yokata, some a distance away frcm it. The latter is also an old valley formed by the River Zindu.
(2) This district forms an interesting study in the topographic results of faulting and overlapping of strota. (Fig. 3)
One of the most striking instances of fault scarps is found along River Atotu, whose walls form a prominent escarpment for a great distance. The connection cf this fault scarp with earthquakes has been referred to by Dr. Imamura.
(3) There are many typical terraces on both sides of River Takahara, of which Hongo terrace is the largest. These terraces are chiefly composed of fine sand, tuff, gravel, etc.
The tuff and the tuffaceous material that are accumulated on the upper part of the 2nd and. 3rd terrace are derived from the volcano Yakedake.
(4) Yakedake is the only active volcano in this district. The source of the River Takahara, lies west of the volcano, so that the river always brings down volcanic matterial esfecially tuff.
Conclnsion It is necessary to consider the whole-course of the River Zindu from its source to the sea. This river rises in the southern part of the Hida Mountains and flows into Toyama bay. It is very important to correlate the terraces on both sides of that river in longitudinal section (Fig. 4). There appears to be a certain relation between the curve of the grade and the height of each terrace.
Points like Sokol's “Wende-punkt” are found in five places in this region. Four of them are the results of faulting.
The history of this region does not begin with the time when block-faulting took place. Long prior to this were periods of mountain elevation, and, no dcubt, tilted upheavals of the whole region. The upward movement of such, areas has given rise to plateaus. Such as Hida, while the downward movement has resulted in drowned seas, like Toyama Bay.
